The Durham seamer is expected to feature in the side's final warm-up match before they take on Pakistan in a three-day Test match in Dubai next week.
"I want to try and prove a point to Andy Flower and Andy Strauss that I'm good enough to be here and stay," The Guardian quotes Onions as saying.
"Now that I'm up for selection it's important for me to come in and get back to my form of 2009. That seems a long time ago. I'm here now and I want to make a difference – I want to be part of this team. I'm convinced that with my skiddy type of bowling I'll do quite well out here."
The 29-year-old suffered a stress fracture in his back in 2010, keeping him out of international cricket for almost two years.